Hydraulic tracer valve



v. RuzlcK ETAL 2,994,502

HYDRAULC TRACER VALVE 4 Sheets-Sheet 1 Aug. 1, 1961 Filed Deo. 23, 1957 wcron Ruz/ck a HAR/Pr c. M/x, INVENTOR.

HERZ/c a .lessa/P,

A TTORNEYS WW1 QS QSSQ 350m `N Al1g 1, 1951 v. RuzlcK ETAL 2,994,502

HYDRAULIC TRACER VALVE Filed Dec. 23, 1957 4 Sheets-Sheet 2 if i [66 /6/ VICTOR RUZ/CK 8 HARRY C. MIX, /20 INVENTOR.

HERZ/6 JESSUP, BY ATTORNEYS www@ Aug.l 1, 1961 v. RuzxcK ETAL 2,994,502

HYDRAULIC TRACER VALVE Filed Dec. 25, 1957 4 Sheets-Sheet 3 wcToR Ruz/cfr a HARRY c. M/x,

INVENTOR.

HERZ/6 8 JESSUP, BY ATTORNE YS Augl, 1961 v. RuzlcK Erm. 2,994,502

HYDRAULIC TRACER VALVE 4 Sheets-Sheet 4 Filed Dec. 25, 1957 32 20' 206 v/cTo/i Ruz/ck a 204 205 HARRY C. M/X,

i 4 INVENTOR. 200 'l l Hmz/c a Jessup,

/la I /12 BY A rroR/ vsvs United States Patent() 2,994,502 HYDRAULIC TRACER VALVE Victor Ruzick, Fullerton, and Harry C. Mix, Anaheim, Calif., assignors to Machine Works, Inc., Gardena, Calif., a irm Y p Filed Dec. 23, 1957, Ser. No. 704,733 24 Claims. (Cl. 251-3) This invention relates to a hydraulic tracer valve, and more particularly to a hydraulic valve for controlling the actuation of hydraulic cylinders for feeding a work piece or a work table responsive to the movement of a manually operable stylus which is actuated by a template, pattern, or the like, to reproduce the shape or contour of the pattern on the work piece.

It is an object of this invention to provide a new and improved hydraulic tracer valve mechanism which provides a finger-like stylus extending therefrom which is responsive to the contour of a pattern or template for controlling within its housing one or more valves for selectively directing and regulating the ow of a hydraulic system to a working end of a corresponding number of actuating cylinders.

It is another object of this invention to provide a new and improved hand-operable hydraulic tracer valve mechanism whereby the movement of the stylus effects an actuation of a pair of cylinders operating at right angles to each other and of a third cylinder operating in a vertical plane to reproduce a pattern or template in three-dimensional form.

It is a further object of this invention to provide a tracer mechanism of the character described which incorporates improved means within its housing for closely regulating the feed rate of the cylinders.

Another object of this invention is to provide a tracer mechanism of the character described which provides means for preventing actuation of one of these cylinders while another is being actuated, more specifically, to provide new and improved means for locking the stylus against movement in any or all of its directions, whereby the stylus may be locked to prevent movement thereof in one horizontal plane while permitting movement in the other horizontal plane and in a vertical plane; the stylus may be locked to prevent a vertical movement while permitting free horizontal movement; or the stylus may be locked to prevent a vertical movement and a horizontal movement in one plane while permitting horizontal movement in a direction at right angles thereto.

A further object of this invention is to provide simplified means for construction of the valve elements incorporated therein whereby the tracer mechanism may be easily, readily, and economically assembled with a high degree of accuracy.

An additional object of this invention is to provide a new and improved stylus for a tracer mechanism of the type described, wherein the portion of the stylus which is brought into contact with the template or pattern provides a non-frictional engagement with the pattern, while the stylus, itself, is provided with means to prevent rotation thereof.

A still further object of this invention is to provide a new and improved hydraulic tracer valve mechanism which is economical to manufacture, and capable of mass production and interchangeability of parts thereof.

Yet another object of this invention is to provide new and improved means for adjusting the feed rate of the actuating cylinders by providing calibrated control knobs therefor, to facilitate fine adjustment thereof, and enable accurate resetting of the reproduction machine for repetition of the operation on subsequentV parts if so desired.

It is a general object of this invention to provide a new and improved hydraulic tracer valve mechanism which 2 overcomes disadvantages or" prior methods and devices heretofore intended to accomplish generally similar pur-` poses.

These and other objects of this invention will be more readily apparent from the following detailed description of the drawings and appended claims.

In the drawings: l

FIG. 1 is a perspective view, in elevation, illustrating, schematically, a tracer mechanism incorporating a hydraulic tracer valve in accordance with this invention;

FIG. 2 is an enlarged vertical sectional view as taken along the vertical axis of the hydraulic tracer valve illustrated in FIG. 1;

FIG. 3 is a horizontal sectional View as taken on `a line 3 3 of FIG. 2;

FIG. 4 is a horizontal sectional view, with parts shownl in elevation, as taken on a line 4 4 of FIG. 2;

FIG. 5 is a vertical sectional View, with parts shown in elevation, as taken on a line 5-5 of FIG. 2;

FIG. 6 is a fragmentary vertical sectional view, similar to the lower portion of FIG. 2, showing a modiiied form thereof;

FIG. 7 is an enlarged vertical sectional view, with parts shown in elevation, of another embodiment of this invention;

FIG. 8 is a horizontal sectional view as taken on a line 8 8 of FIG. 7; and

FIG. 9 is a schematic view, in perspective, illustrating an installation and hydraulic system for the tracer valve mechanism of the embodiment described in FIGS. 7 and 8.

Referring to the drawings, and more particularly t0v FIGS. 1 through 5, there is shown by way of illustration, but not of limitation, a hydraulic tracer valve, generally indicated by the numeral 16, having a body or housing 11 secured by suitable means to a carriage indicated at 12. The carriage 12 includes a cutter mechanism 13 having a downwardly extending tool shaft 14 to which a cutter tool 16 of suitable form is attached. The cutter tool 16 duplicates a surface 17 of a pattern or template P on a work piece indicated at W as is well known in the art.

The pattern P and work piece W may be suitably secured to the bed of a mill or other suitable machine 18 which is reciprocable in a horizontal plane by an actuator cylinder 19 attached thereto. The carriage 12 is reciprocahly mounted by means not shown and is actuated in a direction at right angles to the direction of reciprocation of the table 18 by a cylinder indicated at 21. The direction of reciprocation of the bed 18 is indicated by the arrowed line 22, the direction of reciprocation of the carriage 12 is indicated by the arrowed line 23, the directions 22 and 23 preferably being substantially perpendicular to each other. Vertical movement of the carriage 12 is effected by -a cylinder indicated at 24 which may be suitably attached thereto to reciprocate the table in a vertical direction as indicated by the arrowed line 26. It is to be understood that the cylinders 19, 21, and 24, thus described, are for illustrative purposes only and not a part of the present invention and will therefore not be further described. It is -also to be understood that although the movement of the bed 18 and the carriage 12 have been designated by the arrowed lines 22 and 23, perpendicular to each other, a cylinder 21 maybe suitably fixed to the bed 18 to reciprocate the bed in the direction 23 or the cylinder 19 may be secured to the carriage 12 for reciprocation of the carriage 12 in a direction of the arrowed line 22, with slight modiiication of connecting iiuidY conduits to be further described for control of the cylinders. Similarly, the cylinder 24 may be adapted to effect a vertical travel or reciprocation of the bed 18, instead of the carriage 12, with corresponding modification of the hydraulic conduit connections from that which will be described.

The housing 11 may, if esired, be made of a singular piece of metal or other suitable material, but as best seen in FIGS. 2 and 4, comprises an intermediate body portion27 having-horizontal extensions 28 and -29 extending at right angles therefrom. An upper housing portion 31 and a lower housing extension 32 are preferably separable housing portions, secured to the intermediate housing portion 27 as by bolts 33 and 34, respectively.

The housing 11 is generally of a hollow construction, the housings 28, 29 and 31 each having an enlarged bore 36 in which a bushing 37 is non-rotatably disposed.

l The bore 36 of the upper housing 31 is substantially coaxial with a vertical axis 38 of the housing 11, the axis 38 Vbeing common with the housing 31 and the intermediate housing 27, to yform a common vertical axis.

The bore 36 of the horizontal housing 28 is substantially coaxial with a horizontal axis 39 of the housing 28 and the bore 36 of the horizontal housing 29 is substantially coaxial with a horizontal axis 41 of the housing 29. The axes 39 and 41 are on horizontal planes, substantially perpendicular to each other, and intersect at the vertical axis 38. The axes 39 and 41 are spaced vertically along the axis 38, so that the axis 39 is slightly above the axis 41.

Each of the bushings 37, together with their associated parts to be described, form valve means within the housing 11. The bushing 37 of the housing 28 yforms a valve means 42 for controlling the horizontal bed-actuating cylinder 19. The bushing 37 of the housing 29 forms a valve means 43 for controlling the horizontal carriageactuating cylinder 21. The bushing 37 of the housing 31 forms valve means 44 for controlling the vertically operating carriage-actuating cylinder 24.

' Each bushing 37 is preferably of a laminated construction, each having a plurality of laminations 46, having a common circumferential surface 47. The laminations 46 are preferably secured together as by elongated bolts 48 extending therethrough. The outer circumferential surface 47 is preferably equal to or slightly greater than the bore 36, the bushing 37 preferably being thermally installed within the bore 36. A very satisfactory method of installation has been found by forming the bushing 37 with a slight interference fit with its bore 36, chilling the bushing 37 to reduce the outer diameter thereof and heating the housing 11 in order to expand the inner diameter of the bore 36, whereby the bushing 37 may be easily installed in proper relationship to the housing and the temperatures allowed to become normal. The bore 36 and the outer diameter of the bushing 37 thus resume their normal dimensions and the housing 11 clamps the bushing securely in a non-rotatable and non-leaking relationship.

, Each bushing 37 is provided with a longitudinal bore 49 extending therethrough, said bore having a sliding fit with a piston element. The piston elements are designated as 51 for the valve 42, 53 for the valve 43, and 54 for the vertical valve 44, the valve elements 51, 53 and 54 being substantially identical. The laminations 46 of each bushing 37 are suitably cored to provide spaced enlarged cavities along the longitudinal axis thereof, selective laminations being provided with radial ports or passages communicating between the cavities and the outer region of the bushing 37.

More specifically, the centermost lamination 46 is provided with an enlarged bore, to form an annular space or cavity 56 surrounding its piston member, and a radial passage 57 communicating between the cavity 56 and a longitudinal well 58 formed by slotting the outer periphery of the centermost lamination and adjacent laminations. The well 58 registers with a radical -port 59 of the housing extension 28 which threadedly receives a suitable hydraulic fitting and conduit 61. The port 59 is connected by the hydraulic conduit 61 to the pump side of a hydraulic system (not shown) to receive fluid under pressure and communicate said fluid to the cavity 56.

The laminations 46 adjacent the centermost lamination 4 are suitably partially cored to provide annular cavities 62 and 63, the lamination having the cavity 62 further providing a radial passage 64 lwhich communicates with a longitudinal well 66 formed by slotting the outer periphery of the laminations at a point approximately 90 from the well 58, and the lamination having the cavity 63 providing a radial passage 67 communicating between the cavity 63 and a longitudinal well 68 formed similarly to the wells 66 and 58and located at approximately 180 from the well 66.

As best seen in FIG. 5, the wells 66 and 68 communicate with Vvertical bores 69 and 71, respectively, formed in the housing extension 28 which are connected as by suitable hydraulic conduits 72 and 73, respectively, to the cylinder 19 which actuates the bed 18. The conduit 72 is connected to the left working end (as seen in FIG. l) to draw the bed 18 to the right in the direction of the arrowed lines 22, as seen in this ligure, while the conduit 73 is connected to the right working end of the cylinder 19 to push the table bed 18 to the left, as seen in this figure, when charged with hydraulic fluid as will be hereinafter described.

The endmost laminations 46 of the bushings 37 are partially cored by providing enlarged bores to form annular cavities 74 and 76 which are connected as by radial passages 77 and 78 (FIG. 2), respectively, to an exhaust well 79 (FIGS. 2 and 5) formed at approximately 180 yfrom the Well 58. The well 79 communicates with the reservoir (not shown) of the hydraulic system as through a horizontal bore 81 of the housing and a conduit 82.

The piston members 51, S3 and 54, as previously meutioned, are substantially identical in configuration and have sliding fits within a corresponding bore 49 of the bushings 37. Each piston is formed with a bifurcated head 83 and a pair of circumferentially relieved portions 84 and 8S to form an intermediate unrelieved land 86 and an unrelieved outer end 87. The land 86 is preferably of sufficient width to close off the cavity 56, when so centrally positioned, as illustrated in FIGS. 2 and 4. The relieved portions 84 and 85 are preferably of sufficient width to connect adjacent cavities, for example, the relieved portion 84 connecting the cavity 74 to the cavity 62, or the cavity 62 to the cavity 56 when so positioned, and the relieved portion 85 connecting the cavity S6 to the cavity 63 or the cavity 63 to the cavity 76, when so positioned.

. In the centermost position of the piston member 51, the land 86 closes off the annular cavity 56, therefore closing the inlet fluid pressure conveyed to the Well 58 and the passage 57 by the conduit 61. In this position, the piston end 87 closes the cavity 76, and the unrelieved head portion 83 closes ofl` the cavity 74. When the piston member 51 is moved to the right, as seen in FIGS. 2 and 4, the relieved portion 84 will connect the annular cavity 56 to the annular cavity 62, connecting the fluid under pressure of the cavity 56 through the bore 49 into the cavity 62 and through the passage 64 and the well 66 to the vertical bore 69 and the conduit 72 to convey fluid under lns pressure to the left working end of the cylinder 19, thereby moving the bed 18 in the direction of the arrow 22, to the right. Simultaneously, the relieved portion will connect the cavity 63 to the cavity 76 through the bore 49, and permit hydraulic fluid to return from the cylinder 19 through the conduit 73 and into the vertical bore 71, the well 68, the passage 67 (FIG. 4) and the annular cavity 63, through the bore 49 to the cavity 76. From the cavity 76, the fluid is returned through the passage 78 and well 79 (FIG. 2) to the bore 81 and conduit 82 and thence to the reservoir.

When the piston member 51 is moved inwardly or to the left, as seen in FIGS. 2 and 4, the inlet pressure cavity 56 is connected to the outlet cavity 63 by means of the relieved portion 85 of the piston to admit fluid under pressure from the conduit 61 to the conduit 73 connected to the right Working end of the cylinder 19 to push the table to the left along the direction of the arrow 22 as seen in FIG. 1. Simultaneously, the relieved portion 84 connects the cavity 62, which communicates through the conduit 72 with the left side of the cylinder 19, to the cavity 74 to exhaust the uid from the cylinder to the reservoir.

As previously mentioned, the valves 42, 43 and 44 are similarly constructed, that is, having identical bushings 37 and piston means 51, 53 and 54, respectively, and therefore like parts of the valve members will be referred to by like numbers.

As best seen in FIGS. 1 and 4, the valve means 43 incorporates a bushing 37 having the piston member 53 slidably mounted therein. When the piston member 53 is moved outwardly, or upwardly as viewed in FIG. 4, the inlet annular cavity 56 is connected by the relieved piston portion 84 to the annular cavity 62 to admit fluid through the passage 64 and Well 66 to a vertical bore 69 of the housing 29 and thence through a conduit 88 to the outer working end of the cylinder 21 to push the carriage 12 in a forwardly direction as indicated by the arrow 23. Simultaneously, a conduit 89 connected to the inner end of the cylinder 21 exhausts fluid from the cylinder through a vertical bore 71 of the housing 29 and into the well 68 and passage 67, the annular cavity 63, the relieved portion 85 and into the annular cavity 76 which is connected similarly to the valve 42 to an exhaust bore 81 of the housing 29 communicating with the reservoir as by a conduit indicated at 91. An inner movement of the piston means 53 reverses the flow of fluid to the cylinder 21, by connecting the pressurized annular cavity 56 to the outlet cavity 63 to supply uid through the conduit 89 to the inner end ofthe cylinder 21, and exhausting the uid from the cylinder through the conduit 88.

The vertical valve member 44 of the housing extension 31 is similarly provided with a laminated bushing 37 having the piston member 54 slidably disposed therein. In this instant valve means 44, it has been found more convenient to locate the conduits connecting the cavities to cylinder 24 at the upper end of the housing 31. For this purpose, vertical bores 92, 93, 94 and 96 are provided, extending from the upper outer region of the housing 31 to horizontal bores 97, 98, 99 and 100, respectively. The bores 97-100 (FIGS. 2 and 3) may, for convenience, be bored from the outer surfaces of the housing 31, as indicated by the broken lines 101, shown for the bore 100 in FIG. 3, and plugged as by a plug 102, also shown in broken lines, to seal the passages from the exterior. For clarity, the bores or passages 97 through 100 are herein illustrated as beginning at the bores 92-96, respectively.

rlhe bore 92 forms an inlet passage and is connected to the pressure side of the hydraulic system -as by a conduit 103 to receive uid under pressure from the pump. The fluid under pressure is communicated to the cylinder 24 as by movement of the piston means 54 whereupon upward movement of the piston (FIG. 2) connects the annular cavity 56 to the annular cavity 62 which, through a radial passage like 64 and a well 66, admits the fluid to the horizontal bore 100, the vertical bore 96 and through a conduit 106 to the lower working end of the cylinder 24 to activate the cylinder and thereby raise the carriage 12. Simultaneously, lluid from the other end of the cylinder 24 is discharged through a conduit 104 and into the vertical bore 93, the horizontal bore 98, and through the well 68 and its radial passage 67 to the annular cavity 76 which communicates with the reservoir through the radial passage 78, well 79, horizontal passage 99, vertical passage 94, and conduit 107. When the valve member is pulled downwardly, the direction of flow of fluid under pressure is reversed, and the pressure is admitted to the cylinder 24 through the conduit 104 and discharged through the conduit 106, to lower the carriage 12.

Means for tracing the contour of a pattern or template P, in the form of a stylus 110, is tiltably disposed in the housing 11. substantially along the vertical axis 38, extending through the housing extension 32 and outwardly. therefrom. The stylus includes an elongated shaft 111 having a reduced lower portion 112 to which a sleeve 113 is rotatably mounted. The sleeve 113 may be rotatably fixed to the shaft portion 112 by securing a split washer 114 ou the upper portion thereof 4as by screws or bolts 116. The shaft portion 112 is preferably pro vided with an annular land or shoulder 117 which is encased by the upper portion of the sleeve 113 and the split washer 114. The housing extension 32 is provided with a longitudinal bore `118 communicating with the interior of the housing 27 and having a lower internally tapped portion 119 in which an externally threaded thimble 120 is removably disposed. The thimble 120 includes an upper or inner wall 121 andan open end 122. The shaft 111 extends through a clearance hole 123 of the wall 121 and outwardly through the open end 122. A coil spring 124 is disposed circumjacent the shaft 111 and bears at its upper end against a shoulder formed by a wall 121 of the thimble 120 and at its lower end against the split washer 114 to urge the shaft downwardly and form a stabilizing means against undue vibration and/or movement. A spring-urged detent 126 is preferably radially disposed in the wall of the housing 32 to bear against the external threads of the thimble 120 and tend to prevent the thimble 120 from inadvertent rotation after a desired adjustment has been made.

A guide means in the form of a sleeve member 127 is reciprocably and rotatably disposed within the bore 118 of the housing 32 and includes pressed therein, a self-aligning bearing member 128 through which the shaft 111 slidingly extends. The lower end of the sleeve member 127 rests on the wall 121 of the thimble 120 and reciprocates upwardly or downwardly as determined by the position or the depth to which the thimble is threaded within the tapped portion 119 of the bore 118. The

upper portion of the shaft 111 is non-rotatably secured to a coupling 129 as by set screws, or the like. A spacer sleeve 131 is disposed on the shaft 111, its lower end bearing against the self-aligning bearing 128, and its upper end bearing against the coupling member 129.

A stub shaft 132 is secured in the upper end of the coupling 129 as by a set screw, or the like, and extends upwardly to terminate in a bifurcated clevis tting 133 at its upper end. The stub shaft 132 extends through a pair of horizontally disposed upper and lower links 134 and 136, respectively, and has a sliding rotatable engagement therewith.

As best seen in FIGS. 2 and 4, the link 134 includes a clevis portion 137 having a self-aligning bearing pivotally disposed over the shaft 132 and is adjustably secured to an outer clevis portion 138 which is pivotally secured to an inner bifurcated end 139 of the piston member 51, as by a pin 141, to connect the stylus 110 operatively to the piston member 51. The link 136 is similarly constructed with a clevis portion 142 pivotally mounted on the vertical shaft 132 and having adjustably secured thereto a clevis portion 143 (FIG. 4) which is pivotally secured as by a pin 144 to the inner bifurcated end 146 of the horizontally disposed piston member 53.

A third link member 147 (FIG. 2) is pivotally secured by a clevis portion 148, at its lower end, to the bifurcated fitting 133 of the shaft 132 as by a pin orbolt 149. The link 147 is secured at its upper clevis portion 151 to the inner bifurcated end 152 of the vertically disposed piston member 54 of the valve means 44, as by a pin 153, thereby transmitting the axial movement of the stylus 110 to the piston 54.

The links 134, 136 and 147 are preferably provided with self-aligning bearings at each clevis end for a reason which will be more apparent from. the description following.

As will be apparent from the foregoing description, the stylus 110 is positioned within the housing 11 and extends outwardly therefrom and is provided at its lower end with a rotatable sleeve 113 forec'onta'ct with Va, ternplateV or pattern to be duplicated. The sleeve 113 is manually held against the pattern P. Following of the pattern is'facilitated by virtue of Ythe fact that the sleeve 113 is rotatable and therefore provides a non-frictional engagement with the pattern. As the stylus 110 is urged against the pattern, the stylus is pivoted or tilted about a point 155 at the intersection of a horizontal axis of the guide member, which includes the sleeve 127 and selfaligning bearing 128, and the vertical axis 38 along whichY the stylus is positioned. As the lower end 112-113 of the stylus 110'responds in a direction dictated by the pattern, that is, inwardly or outwardly, as the pattern undulates, the upper portion, i.e., the coextensive portion 132 is tilted in an opposite direction, thereby actuating one of the links 134, 136 and translating the tilting movement of the stylus 110 into an axial movement of the pistons 51, 53, respectively. lf, as viewed in FIG. 2, the stylus lower portion 112-113 is tilted to the left, the upper portion 132 is tilted to the right, pushing on the link 134 to actuate the piston member 51 in a direction to the right, causing the fluid pressure to communicate through the conduit 72 to the left working end of the cylinder 19 (FIG. l) to push the bed 18 to the right, as viewed in this figure, until the cutter 16 duplicates the depth of the configuration at this point of the pattern P and the stylus 110 resumes a dead-center or vertical position. When the stylus 110 assumes a vertical position, the piston member 51 is returned to its normal centered position, cutting off the pressure from the conduit 61 and thereby stopping the motion of the bed 18.

In the event that the stylus 110 is tilted towards the right, the upper end 132 is tilted towards the left, as seen in FIGS. 2 and 4, and the piston member 51 is shifted within the valve member 42 to cause fluid under pressure to communicate with the right end of the cylinder 19 as through the conduit 73, thus causing the cylinder 19 to push the table bed to the left, as seen in FIG. 1, until the cutter 16 reproduces the depth on the work piece W that the stylus 110 has responded to on the pattern P and therefore return the stylus 110 to its normal vertical position whereby the ow of fluid pressure is cut off.

As illustrated in these drawings, the cylinder 19, which responds to the left and right movements of the stylus 110, as seen in FIGS. l and 2, is attached to the bed 18. Therefore, when the stylus 110 is tilted to the right when responding to the configuration of the pattern P, the cutter 16, which is carried by the same carriage 12 that the tracer head is attached to, must then be conveyed in a direction opposite to the movement of the stylus to bring the stylus back to its original vertical position and shut oir the valve means 42. This movement in a direction opposite to that of the stylus, brings the cutter 16 into the work piece W to duplicate the configuration of the pattern P.

vIn the event that the lower portion 112-113 of the stylus 110 is tilted forwardly, as seen in FIG. 2, the upper extension portion 132 is tilted rearwardly, causing the link 136 to actuate the valve member 53 of the valve means 43. This forward movement of the lower stylus portion causes the piston member 53 to be extended outwardly or, as Vseen in FIG. 4, upwardly to connect the pressure cavity 56 to the outlet cavity 62, thereby communicating the uid under pressure to the outer end of the cylinder 21 through the conduit 88. This action causes the cylinder to push the carriage 12 forwardly in a direction indicated by the arrowed line 23 to move the tracer head 10 forwardly and allow the stylus 110 to resume a normal vertical position and thereby return the'piston 54 to its centermost position where the pressure to the cavity 56 is shut off and movement of the carriage 12 is stopped.

In the event that the stylus bottom portion 112-113 is tilted rearwardly, from the plane shown in FIG. 2, the

action is reversed from that described above, causing the upper portion 132 to Apull the piston member 5 3 forwardly, towards the vertical axis 38, and cause tluid pressure to enter the cylinder 21 at its inner end through the conduit 89, and exhaust fluid therefrom through the conduitv 88, through its corresponding cavities and passages within the valve member 43 and the conduit 91, to the reservoir, as previously described.

The valve means 44, which controls the cylinder 24, causing vertical travel of the Vcarriage 12, is responsive to vertical movement of the stylus 110. If the stylus 110, in responding to a contour of the pattern P, is pushed upwardly, the clevis tting 133 and link 147 pushes the piston member 54 upwardly to allow fluid pressure to communicate with the lower end of the cylinder 24 as through the conduit 106 and thereby lift the carriage 12. In the event that the stylus is lowered along the axis 38, the piston member 54 is pulled downwardly, causing `iluid pressure from the conduit 103 to be diverted into the upper end of the cylinder 24 as through the conduit 104 to lower the carriage 12. As in the other table and bed movements, the cutter 16 carried by the carriage 12 is urged by the vertical movement of the carriage 12 to reproduce the height or depth to which the stylus 1-10 was moved responsive to the pattern P. When the cutter 16 has reached the corresponding point of the stylus 110, the piston 54 again resumes its centermost position to shut off fluid pressure and stop movement of the carriage 12.

It will now be more clearly understood that with the provision of self-aligning bearings at all pivot and attachment points of the links 134, 136, 147 movement in horizontal and vertical directions is best facilitated.

To prevent transmission of motion of the stylus in one plane to the valve means corresponding to movement of another plane, the stylus is preferably restricted against undue rotational movement. For this purpose, a transverse pin 156 preferably extends from the stylus shaft 111 at a point spaced above the point of rotation of the stylus, and has an end 157 extending into a transverse opening 158 of the housing extension 32. The opening 158 is preferably slightly larger than the end 157 of the pin 156 to allow slight movement thereof, as required by the movement of the stylus in the vertical and horizontal planes. However, as the pin 156 is located at a distance from the point 155 which is considerably shorter than the distance from the working end 132 of the stylus from the point 155, a very small clearance is required to permit desired movement of the stylus. It has been found that a clearance of about 1A@ of an inch is sufcient to allow the stylus 110 to respond freely to the contour of the pattern, yet limit the rotation of the shaft 111 sufciently, whereas undesired transmission of motion from the stylus to a valve means is prevented.

The feed rate of the cylinders 19, 21 and 24 is controlled by the volume of fluid under pressure supplied to the cylinders. More specifically, as the movement of the piston members 51, 53 and 54 increases in the respective ,valve means, the volume of uid supplied to the cylinders 19, 21 and 24 increases, thereby increasing the rate of speed at which the cylinders actuate. In some applications of reproduction of a pattern, for example where a repetition of operations is desired, as in making a plurality of duplications from the same pattern, calibrated means are preferably provided for adjusting the feed rate of the cylinders. Such means of adjusting the feed rate includes the provision for limiting the amount of axial movement of the piston members within the valve means, thereby restricting the ow of fluid under pressure to the cylinders.

To this end, the valve means 42 is provided with an adjustment means or stop member 160 which compirses a threaded shaft 161 extending through a tapped transverse aperture 162 of'a cap 165 for the extension 28. The member 160 preferably includes a vknurled knob 163 having suitable indicia 164 calibrated on a portion-therea99-Moe 9 of. By rotating the knob 163, the member 160 may be extended inwardly towards the end 87 of the piston member 51 or retracted frrm the end. In accordance with the spacing of the inner end of the threaded shaft 161 from the outer face of the piston member 51, the outward movement of the piston 521 is thereby limited.

To limit the inward movement of the piston 51 (to the left, as seen in FIGS. 2 and 4), a stop member 166 is preferably provided in the housing 11 and on the horizontal axis 39 to limit the tilting action of the upper portion of the stylus member 110 to the left. The stop member 166 includes an externally threaded sleeve 167 disposed in an internally threaded opening in the wall of the intermediate housing section 27, opposite the extension 28. The sleeve 167 has non-rotatably secured thereto, an enlarged gear 169 which meshes with a reduced gear 171 secured to an elongated shaft 172 rotatably mounted in the housing 11. The shaft 172 preferably extends through the housing 11 and has an inner end 173 thereof rotatably mounted in the section 27 of the housing and an outer end extending through an aperture 174 of the section 28 to extend outwardly thereof in the vicinity of the adjustment means 160. A knurled knob 175, having suitable indicia or calibrations 176 thereon, is secured to the outer end of the shaft 172 to facilitate rotation of the shaft and permit an operator to predetermine the position of the stop member 166. Indicators (not shown) are preferably printed or otherwise marked upon the exterior of the cap 163 to facilitate indexing and registering of the indicia 176 and 164. As the shaft 172 is rotated by the knob 175, the gear 171 rotates the gear 169, thereby rotating the threaded sleeve 167. As determined by the direction of the rotation of the shaft 172, the sleeve is extended or retracted within its threaded aperture to advance or retract the stop member 166 relative to the clevis portion 137 of the link 134.

If desired, the stop member 166 may be advanced by rotation of the shaft 172 and knob 175 until the member 166 abuts the clevis portion 137 of the link 134 and thereby prevents any movement of the link and its corresponding piston member 51 to the left, as seen in FIGS. 2 and 4. Likewise, the member 160 may be rotatably extended inwardly to abut the outer end of the piston member 51 to prevent outward movement or movement to the right as seen in FIGS. 2 and 4. To increase the versatility of adjustment, if desired, the stop member 166 may be additionally provided with an inner threaded member indicated at 177 to adjust the position of an inner end 178 thereof relative to the sleeve 1,67.

Calibrated means for adjusting the amount of movement of the piston member 53 is also preferably provided. Such means comprises a reciprocable stop member 180, see FIG. 4, threadedly engaging a cap 181 of the valve means 43 and having a threaded shaft 182 rotatable by `a knob 183. Shiitable indicia 184 are preferably provided tov facilitate visual registering of the stop member 180 relative to an index or mark (not shown) on the cap 181. An `additional stop member 185 is provided at the opposite end of the axis 41 to limit the inward movement of the piston 53. Stop means 185 includes an inwardly extending threaded shaft 186 and an ac-tuating knob 187, the inwardly extending portion 186 being reciprocable to abut the clevis portion 142 of the link 136 or be spaced therefrom to limit the motion of the piston 53, as desired. As illustrated in FIG. 4, Where both the stop members 180 and 85 are shown in a zero position, that is, where movement of the piston 53 is completely stopped, the inner end 182 abuts against the outer face of the piston 53 while the inner end 186 `of the stop member 185 abuts the clevis portion 142 of the link 136, thereby prohibiting movement thereof. It will be noted that although movement of one of the pistons like piston 53, is prohibited by its stop or limiting members, 180, 185, the movement of the other piston 51 in a horizontal plane is unhampered, providing that the stop members 160 and 166 are positioned to permit movement thereof. 'Iher-V fore, the valve means 42 may be permitted to operate while the valve means 43 is restricted from operation, and likewise the valve means 43 may be permitted to operate while the valve means 42 is inoperative.

Means are also preferably provided for limiting or eliminating vertical motion of the stylus and of its associated cylinder 24. A-t the upper end of the housing extension 31, a rotatable stop member i190 is threadedly disposed substantially on the axis 38 and in a threaded aperture of a cap member 192 of the housing 31. The stop member 190 includes a threaded shaft 191 which may be extended into engagement with the piston 54 of the valve means 44 to prohibit upward movement of the piston or retracted to space the pin 191 from the piston 54 to permit upward movement of the piston 54. Suitable indicia 193 are preferably provided `on a knurled knob 194 to facilitate accurate adjustment of the volume of ow and therefore the -feed rate of the cylinder 21.

To prevent inward or downward travel of the piston 54, the tbimble may Ibe threaded inwardly of the housing 3-2 until any slack between the sleeves 131, 127 and the wall 121 of the thimble 120 is taken up. When the thimble 120 is fully threaded inwardly, the wall 121 pushes the sleeve 127 upwardly until the self-aligning bearing 128 clamps the sleeve 131 against the coupling 129, thus forming a continuous and solid connection between these parts. Thus, downward travel of the stylus 110 is prevented because, as the stylus end 113 is pulled downwardly, the coupling 129 to which the shaft 111 is secured bears against the sleeve 131 which is in contact with the bearing 128 fixed Within the sleeve 127.

If it is desired to release the stylus for vertical travel, the thimble 120 is unscrewed, allowing the sleeve 127 to be free as determined by the distance that the thimble 129 has been unscrewed. Suitable indicia 195, see FIG. l, are preferably provided on the outer periphery of the thimble 120 and registerable with an index marker 196 on the outer face of the housing 32 to accurately set the distance desired. Likewise, the locking means 190 may be retracted as shown in FIG. 2, to provide a gap between the end of the threaded shaft 191 and the upper face of the piston l54, as indicated -by the indicia 193, to determine the limit of the upward movement as desired.

It will now be more apparent that the vertical travel of the stylus 110 can be limited or prevented without restricting the tilting motion of the upper end 132 in the event that the other locking means --166, and 180- are not brought into engagement with their complementary parts. It will also be apparent that one of the horizontal and the vertical movements can be prohibited While the remaining horizontal plane movement is permitted or both horizontal movements can be prohibited while permitting a vertical movement of the stylus.

Therefore, the tracer head as described above may be used as a one-way, two-way, or three dimensional tracer head as required by the pattern to duplicate the pattern upon a work piece.

The feed rate of the cylinders may be adjusted by adjusting the position of the stop members 160-166, 180- 185 and 190-120 whereby the movement of their respective piston means is governed by the position of the stop members. The indicia on the stop members may be interpolated to set the feed rate at a desired rate.

Referring to FIG. 6, a modified embodiment of the invention is illustrated, wherein like parts are referred to by like numbers. In this instant embodiment, only the lower portion of the housing 32 is shown, the rest of the construction being substantially identical to that of the first embodiment.

A thimble '200 is shown having an externally threaded portion 201 engaging internal threads of the housing 32, and having an end wall 202 in engagement with a sleeve 203. in, which the self-aligning bearing 155 is fixed. The shaft 111 of the stylus 110 extends through the. bearing 11 ,Y n 155 and is secured at its lower end 112 Ato a rotatable sleeve 113. The sleeve 113 is prevented from axial movement as by a split washer 1-14 and shoulder 117 similar to the rst embodiment.

The thimble 200 of this embodiment, however, includes an internally threaded portion 204 in which a nut 205 is threadedly disposed. The nut 205 bears upwardly against a flanged washer 206 which has a sliding engagement with the shaft 111. The washer 206 forms a spring retainer for one end of the spring 124 extending between the washer 206 and the wall 202. If it is desired to facilitate movement of the stylus 110 by manual means, the nut 205 may be screwed inwardly -to relieve the tension of the spring 124 against the split washer 114 allowing the stylus 110 to move more freely. If additional tension is desired, the nut 205 may 'be unscrewed to allow the washer 206 -to bear against the washer 114.

Referring to FIG. 7, another embodiment is shown, in which the response to a template or pattern is in one horizontal plane and in one direction only, commonly known as a 180 valve control. In this type of actuation, the valve member 210 is mounted on a carriage 246 which is reciprocated along a horizontal plane as by a screw machine, hydraulic cylinder feed, or other means (not shown). The type of pattern to which a valve tracer head of this type is applied is generally an elongated strip or sheet P having one or more edges thereof in an undulating, or other, configuration. The valve is thus carried, by the means mentioned above, longitudinally on the bed in a direction substantially parallel to the template, and the valve body 210 is rponsive inwardly and outwardly to follow the undulations.

The tracer valve mechanism 210 comprises a body 211 having a longitudinal bore 212 in which a bushing 213 substantially identical to the bushing 37 is disposed. The bushing 213 is preferably laminated, the laminations being bolted together by bolts like 48 of the bushing 37, and non-rotatably fixed in the body 211 as by the thermal method described for the first embodiment, in which the body 211 is heated to expand the bore 212 and the bushing 213 is refrigerated to reduce the outer diameter thereof and facilitate insertion of the bushing within the bore 212. When the temperatures of the parts 211 and 213 return to a common room temperature, the parts are securely and non-leakingly assembled. The laminations 214 of the bushing 213 are suitably cored to provide an inlet pressure passage 216, exhaust passages, like passages 77, 78 of the first embodiment, and outlet passages 218 and 219 which communicate with the cylinder 248.

The bushing 213 is provided with a longitudinal bore 221 extending therethrough in which a piston member 222 is slidingly disposed for reciprocation therein. The piston member 222 is circumferentially relieved as at 223 and 224 to provide an intermediate land 226 sutiicient in width to close off an annular cavity communicating with the inlet passage 216, when so positioned. The relieved portions 224 and 223 further connect the inlet pressure passage 216 to either of the passages 218 and 219, when so positioned, simultaneously connecting a passage 218 or 219 to the exhaust passages like 77, 78 to return the fluid from the cylinder 248. The piston 222 in this embodiment is preferably of a hollow construction, having a bore 227 extending therethrough and having internal threads at the upper portion thereof.

A plug member 228, having external threads is adjustably disposed in the internal threads of the bore 227 and includes a depending projection 229 having an inwardly extending conical face 231 at the end thereof. The plug member 228 includes an upwardly extending elongated shank of reduced diameter, indicated at 232, which extends into a member 233 adapted to be connected to a suitable electric circuit (not shown). The shank 232 is retractable when the solenoid is electrically actuated to move the piston member 222 upwardly against the compressive force of a coil spring 234 inter- 12 posedibetweenv the upper face of the piston `anda down` wardly facing recess 236 of an upper cap member 237. f An elongated stylus member 236 is positioned within thebore 227 of the piston member 222 and is preferably of reduced diametrical dimension to provide an annular space between the stylus and the bore 227. The Stylus member 236 is pivotally secured within an aperture 238 of a lower cap member 239 to permit a tilting action of the stylus 236 in a vertical plane about a pin or shaft 241 extending transversely therethrough. The upper portion 242 of the stylus is provided with an inwardly extending conical face 243 on the end thereof to provide a seat for a spherical member 244 disposed between the conical faces 23-1 and 243.

Referring to FIG. 9, there is illustrated, in schematic form, the operation of the instant embodiment, wherein the valve 210 is illustrated as being progressed by a carriage 246 which travels in the direction of the arrowed line 247 by mechanical means (not shown). For simplicity, a cylinder 248 is shown connecting/directly between the carriage 246 and the tracer valve head 210, although it is to be understood that such mechanical connection may take various forms. The cylinder 248 is preferably arranged to feed the valve tracer head 210 in a direction substantially perpendicular to the direction of travel of the carriage 246 as indicated by the arrowed line 249, feeding the tracer head inwardly or outwardly of the pattern P in response to the configuration of the undulations on the pattern.

As best shown in FIG. 7, the piston 222 is normally urged downwardly by the spring 234, whereby the relieved portion 224 connects the pressure inlet 216 with the outlet passage 218 to communicate with the outer end of the cylinder 248, FIG. 9, as by a conduit 251 to normally feed the tracer head towards the pattern P. As the cylinder piston rod 252 is extended, the tracer head 210 is urged against the pattern P until the stylus 236 is tilted Isuii'ciently to cause the conical surface 243 to push upwardly upon the spherical member 244 seated in the conical surface 231 of the plug 228, thereby raising the piston member 222 and closing off the inlet pressure port 216 to stop the dow of pressure to the cylinder 248. As the tracer head 210 is advanced by the carriage 246, any additional rise indicated at R on the pattern P will cause the stylus 236 to be tilted further, raising the piston 222 higher, to connect, through the relieved portion 223, the pressure inlet 216 with the outlet passage 219 to communicate with the inner end of the cylinder 248 as through a conduit 253 to retract the head 210 from the pattern P, causing a cutter like 16 of FIG. 1, to follow the contour of the pattern. As the tracer head 210 and its associated cutter is retracted, the stylus is allowed to return into its intermediate tilted position whereby the stylus causes the piston member 222 to shut oft the inlet pressure. In the event that the pattern dictates, as in a recess, the stylus 236 is allowed to return to a true vertical position whereby the iow of fluid is again directed to the outer end of the cylinder through the conduit 251 to reverse the travel of the tracer head 210.

If it is desired to rapidly retract the stylus from the pattern, the solenoid 233 may be Iactuated, as by a footoperated switch (not shown), or the like, in a suitable electric circuit, to raise the piston means 222 upwardly against the force of the spring 234 and thereby quickly divert uid pressure from the passage 216 into the passage 219 and conduit 253.

In general, this invention comprises a hydraulic tracer head of the type which is adapted to follow lthe contour of a pattern or template by means of a stylus member positioned within a housing and extending therefrom, and in response to the pattern, actuates one or more valve members which control the ow of hydraulic fluid under pressure into suitable cylinders for causing a corresponding movement in either a carriage which supports the tracer head'or a table bed which supports the pattern, to

cause a cutter to duplicate the contour of the pattern or template on a work piece. This invention features a new and improved stylus means incorporating non-frictional means for following the contour of the pattern and means for preventing rotation of the stylus whereby the re- Spouse of the stylus in one direction, actuating one valve member, does not actuate the valve member which is responsive to actuation of the stylus in another direction. This invention also features improved means for limiting or controlling the volume of fluid under pressure admitted to the cylinders whereby the feed rate is capable of highly accurate adjustment. A further feature of this invention is the provision of such limiting means whereby one or more of the valve means can be locked against actuation while still permitting the use of the remaining valve means. The valve means also includes a simpliied construction resulting in a more precise and accurate machining and assembly, resulting in a faster and more accurate response to the movement of the stylus.

An important feature of the valve member is the provision of enlarged ports or wells whereby a constant pressure is available to bring about a faster and more reliable response to the movement of the stylus.

While we have herein shown and described what we conceive to be the most desired embodiments of our invention, it is to be understood that alterations and modiiications thereof may be made in a manner to satisfy the spirit of our invention which is intended to comprehend any and all equivalent devices as comprehended in the following claims.

What we claim as new and desire to secure by Letters Patent is:

1. A tracer for an hydraulic duplicating machine comprising: a body having a pair of horizontal cavities, the axes of which are substantially perpendicular to each other and vertically spaced from each other along a vertical` axis of said body; means dening a third cavity in said body on said vertical axis and having a lower portion, a manually 'operable stylus in said body positioned substantially along said vertical axis and having an end extending outwardly from a lower end of said body for engagement with the pattern; rotatable guide means mounted in said lower portion of said third cavity, said stylus extending through said guide member and having a sliding t therewith and being vertically movable and pivotable about the point of the intersection of the horizontal axis of said guide member and said vertical axis for tilting said stylus; means delining passages in said body, said passages including an inlet passage, an exhaust passage and a pair of outlet passages communicating with each said cavity, each inlet passage being adapted to receive a iluid under pressure, each exhaust passage being adapted to exhaust uid; a piston valve means slidable in each said cavity for directing the ow of fluid under pressure to selective outlet passages; and link means positively connecting each of said piston valve means and an upper portion of said stylus for translating the tilting motion of said stylus into an axial movement of said piston means for actuating said piston valve means.

2. A tracer mechanism in accordance with claim l wherein said rotatable guide member is slidably mounted for selective vertical reciprocation within said lower portion of said third cavity and including means for limiting vertical movement of said guide member.

3. A tracer mechanism in accordance with claim 1 including means for limiting rotation of said stylus about the vertical axis.

4. A tracer mechanism in accordance with claim 2 including calibrated means coactive with each of said piston valve means for limiting the axial movement of said piston valve means.

5. A tracer mechanism in accordance with claim 4 wherein said calibrated means includes means for selec- '14 movement while permitting the other of said piston valve means to remain operative.

6. A tracer mechanism in accordance with claim 5 i11-l cluding a rotatable sleeve member on the outer end of said stylus for providing a non-frictional engagement with the pattern to be reproduced; and means cooperating between said stylus and said rotatable sleeve member for preventing axial movement of said sleeve member relative to said stylus.

7. A tracer mechanism in accordance with claim 6 in-- cluding spring means for urging said stylus outwardly of said body for engagement with the pattern and for stabilizing the stylus.

8. A tracer mechanism in accordance with claim 7 including means for adjusting said spring means.

9. A tracer mechanism, for an hydraulic duplicating machine which comprises: a housing; a plurality of piston valve means mounted in said housing, a pair of said valve. means being disposed on vertically-spaced horizontal planes and having axes substantially perpendicular to each other, the third of said valve means being disposed in a vertical plane and having an axis perpendicular to said axes of said pair of valve means; each of said valve means comprising a laminated bushing non-rotatably secured in said housing and having a bore therethrough and cylindrical piston means slidably disposed in each said bore; means defining axially-spaced, enlarged cavities in said bushings, said means comprising enlarged bores in selected lamina of the bushings; means defining passages in selected lamina of each bushing and communiV eating between .said enlarged cavities and the exterior of said bushing, one of said passages being arranged to receive fluid under pressure, another of said passages exhausting fluid and two of said passages comprising outlets; each of said pistons having a pair of longitudinallyspaced, circumferentially-relieved portions dimensioned to connect adjacent enlarged cavities of said bushing when so positioned, and unrelieved portions being dimensioned so as to close oi the cavity receiving the uid under pressure when so positioned; each piston having an end extending inwardly into said bushing; a manually operable, elongated stylus means positioned in said housingA substantially along said vertical axis of said third valve means and having a lower end extending outwardly from said housing for engagement with a pattern; a rotatable guide member in said housing having an external sliding i'it with said stylus, said stylus being vertically movable and tiltable about a point of intersection of a horizontal axis of said guide member and the longitudinal axis of said stylus; means for limiting rotation of said stylus about its longitudinal axis, said means comprising a pin, extending transversely from said stylus and having limited movement in an enlarged, transverse bore of said housing; and universal link means positively connecting the upper end of said stylus and each of said ends of said pistons for translating tilting movement of said stylus to a linear reciprocal movement of corresponding pistons, so that the tilting movement of said stylus positions a piston means axially relative to a corresponding bushing to selectively connect said one passage having uid under pressure with one of said pair of passages comprising outlets, and simultaneously connecting the other of said passages to said exhaust passage in said bushing.

l0. A tracer mechanism, as defined in claim 9, wherein said link means is adjustable so as to pre-selectively adjust said piston relative to said bushing and relative to said stylus.

ll. A tracer mechanism in accordance with claim 9 wherein said rotatable guide member is slidably mounted in said housing for selective vertical reciprocation and including means in said housing for adjusting the position of said rotatable guide member.

l2. A tracer mechanism in accordance with claim 9 including means for limiting vertical movement of said tively locking each of said valve means against axial 7 5 stylus.

13. A tracer mechanism in accordancewith claim 12 wherein said means for limiting the vertical movement of the stylus includes means for preventing movement of said stylus. i

14. A tracer mechanism in accordance with claim 13 including adjustment means for limiting movement of said stylus in one of its horizontal planes, thereby adjusting the iiow rate of fluid through an outlet.

15. A tracer mechanism in accordance with claim 14 wherein said adjustment means for limiting the movement of said stylus includes means for locking the stylus against movement in said one of its horizontal planes, thereby preventing movement of its corresponding piston` 16. A tracer mechanism in accordance with claim l including adjustment means for limiting movement of said stylus in the other of its horizontal planes, thereby adjusting the ow rate through another outlet.

17. A tracer mechanism in accordance with claim 16 wherein said adjustment means for limiting movement of said stylus in the other horizontal planefincludes means for locking the stylus against movement in said other horizontal planes.

18. A tracer mechanism in accordance with claim 17 wherein said means for limiting or locking said stylus for movement in each horizontal plane are independent of each other and independently operable.

19, A tracer mechanism in accordance with claim 18 wherein said means for limiting or locking said stylus for movement in a vertical plane is independent of said means for limiting or locking said stylus in horizontal planes and is independently operable.

20. A tracer mechanism in accordance with claim 19 including a rotatable sleeve member on the outer end of said stylus thereby forming a non-frictional engagement with the pattern to be duplicated and means cooperating between said stylus and said rotatable sleeve for preventing axial movement of said sleeve.

21. A tracer mechanism in accordance with claim 20 including spring means in said body for biasing said stylus outwardly of said body for engagement With the pattern and for stabilizing said stylus.

22. A tracer mechanism, for an hydraulic duplicat ing machine comprising; a housing; aY pair of vertically spaced, horizontally disposed valve means slidable on axes at right angles to each other in lsaid housingia spring biased vertical valve means slidable yonan axis at right angles to the axes of said pair of valve means; universal guide means in said housing; a manually operable stylus means in said housing positioned substantially along said vertical axis and extending through said guide means and having a sliding t therewith, said stylus means having one end thereof extending out- Wardly from said housing for engagement with the pattern and being vertically movable and pivotable about the point of intersection of the horizontal axis of said guide means and said vertical axis for tilting said stylus in response to engagement of said one end with the pattern; and universal linkage means connected to an opposite end of said stylus and said valve means for trans lating the tilting motion of said stylus into an axial movement of said valve means.

23. A tracer mechanism in accordance with claim 22 including means for selectively and independently locking each of said valve means against axial movement.

24. A tracer mechanism in accordance with claim 22 including calibrated means associated with each of said valve means for selectively limiting the axial movement of said valve means so as to selectively adjust hydraulic ow rate therethrough.

I References Cited in the le of this patent j UNITED STATES PATENTS 

